Hernandez spent Wednesday evening in his hotel room in New Jersey after being released from hospital after being admitted following training 24 hours earlier. Although medical staff found no major damage, Ferguson has confirmed the Mexico forward will not play for a couple of weeks, even though he will continue to train and remain on tour.
"He got concussion in training and we dealt with that," said Ferguson. "We took him to hospital, he had a scan, it was all clear.
"He is back in the hotel. He is in his room and will be out for a couple of weeks. He would never have been available for Barcelona anyway because he has just come back from his break after the Gold Cup.
"He will travel with us though. He is okay for that."
In Hernandez's absence, Dimitar Berbatov took the opportunity to shine, helping to create United's excellent opener before smashing home the third right after half-time.
Both fulfilled the Bulgarian's preferred criteria of 'beautiful goals' and helped break his duck for the tour.
In between, Park Ji-sung scored a fine goal to maintain his impressive recent form.
The South Korean then indicated he would be willing to sign the two-year contract extension Ferguson confirmed in Seattle last week had been offered.
"Why not?" said the midfielder. "I keep saying I want to stay here for more years to win things with Manchester United. Hopefully one day we will get together."
Source: PA
Source: PA